Part 3 (1/2)

The habit of reflecting on oneself in homuncular terms comes naturally, even though this leaves us caught in a mental hall of mirrors where endless virtual tunnels of self-reflections make it impossible to navigate our way out. There is little reason to expect that evolution would have equipped us with a special set of corrective gla.s.ses for dealing with the problems posed by such self-reflection. It is in the realm of social interaction with other creatures like ourselves that we need tools for navigating the challenges created by ententional processes. We don't have to worry very often why it is that we ourselves do the things we do, and we are seldom caught entirely by surprise by our own actions. But this is often the case with others. It is one of the claimed benefits of years of psychoa.n.a.lysis or meditation that they can provide a modest capacity for intervention in our otherwise una.n.a.lyzed habits and predispositions. But social life constantly demands that we guess at, antic.i.p.ate, and plan for the actions of others. Many students of mental evolution argue that this is a capacity that is only well developed in h.o.m.o sapiens. The ability to develop a mental model of another's experiences and intentions is often given the tongue-in-cheek name ”mind reading” by behavioral researchers. However, despite our comparatively better evolved capacity, we are still notoriously bad at it. Because it is both difficult and fraught with error, we spend a considerable fraction of our days antic.i.p.ating others, and from an early age appear predisposed to project the expectation of another mind into inanimate toys.

So one reason we may tend to think in homuncular terms, even in contexts where rationally we know it makes no sense (as in superst.i.tious behaviors, or wondering at the ”meaning” of some apropos coincidence), is that it just comes naturally. This psychological habit should not, however, absolve us as philosophers and scientists from the requirement that we think more clearly about these issues. And yet, as we will see in the examples discussed below, avoiding thinking this way, without throwing out the baby with the bathwater, is both remarkably difficult to achieve and deeply counterintuitive. Not only do we homuncularize without thinking, even careful theorists who systematically try to avoid these errors often fall easy prey to only slightly more subtle and cryptic versions of this fallacy. For the same reason that the homunculus fallacy is so seductive, it is also a slippery target. Thinking that we have finally destroyed all vestige of this crafty adversary, we often become complacent and miss its reappearance in more subtle and cryptic forms.

As noted in the last chapter, most considerations of ententional phenomena implicitly treat the critical details of their causal dynamics as though they are hidden in a black box, and worse, invoke the causal influence of explicitly absent ent.i.ties. Because of this, researchers in the natural sciences have little choice but to make every effort to avoid a.s.signing explanatory roles to ententional processes in their theories. And wherever a field such as cellular biology or cognitive neuroscience encounters issues of information or functional organization, it treats them as heuristic placeholders and endeavors to eventually replace them with explicit physical mechanisms. Indeed, biologists and cognitive neuroscientists treat this as an imperative, and rigorously scour their theories to make sure they are free of any hint of teleology. In philosophical circles, this methodological presumption has come to be known as eliminative materialism because it presumes that all reference to ententional phenomena can and must be eliminated from our scientific theories and replaced by accounts of material mechanisms.

But can this eliminative strategy be carried out exhaustively such that all hint of ententional explanation is replaced by mechanistic explanation? And even if it can, will the result be a complete account of the properties that make life and mind so different from energy and matter? I have little doubt that a universe devoid of ententional phenomena is possible. In fact, I believe that at one point in the distant past, the entire universe was in just such a state. But that is not the universe in which we now live. For this reason, I believe that this eliminative enterprise is forced to sacrifice completeness for consistency, leaving important unfinished business in its wake. We need to explain the ententional nature of our own existence, not explain it away.

HEADS OF THE HYDRA.

Since the Enlightenment, the natural sciences have progressively dealt with the homunculus problem by trying to kill it. The presumption is that it is illegitimate as an explanatory principle, and worse, that accepting it risks readmitting G.o.ds, demons, and other such supernatural surrogates and argument-stoppers back into the discourse of science. As the philosopher Daniel Dennett rightly warns, accepting these sorts of explanations incurs a serious explanatory debt.

Any time a theory builder proposes to call any event, state, structure, etc., in any system (say the brain of an organism) a signal or message or command or otherwise endow it with content, he takes out a loan of intelligence. . . . This loan must be repaid eventually by finding and a.n.a.lysing away these readers or comprehenders; for failing this, the theory will have among its elements una.n.a.lysed man-a.n.a.logues endowed with enough intelligence to read the signals, etc.2 Homunculi are stand-ins for incomplete explanations, and since, according to current scientific canon, good explanations should take the form of mechanistic a.n.a.lysis, all references to the teleological properties attributed to homuncular loci need to be replaced by mechanisms. But often, efforts to explain away blatant homunculi lead to their unwitting replacement with many less obvious homunculi. Instead of a little man in the head, there are sensory maps; instead of an elan vital animating our bodies, there are genes containing information, signaling molecules, receptor sites, and so on, to do the teleological work.

This reminds me of the cla.s.sic tale of Hercules' battle with the Hydra. The Hydra was a monster with many heads. The very effort to cut off one of the Hydra's heads caused two more to grow where the one had been before. In the story, Hercules' helper Iolaus prevented the regrowth of new heads by searing each neck with flame as each head was chopped off, until eventually the one immortal head was also removed and buried under a boulder. The head might rightly be described as the organ of intention: the source of meaning and agency. As in the story, the effort to remove this organ of intention only compounds the challenge, progressively ceding power to the foe one is trying to subdue, because it reappears in other places. In the modern theoretical a.n.a.logues of this myth, positing a locus of ententional cause merely pa.s.ses the explanatory buck to an as-yet-to-be-explained process occurring at that locus or elsewhere, that serves this same role-only less obviously. The process is thus implicitly incomplete, and possibly not even able to be completed, requiring a similar effort at some later point in the a.n.a.lysis to deal with these new creations. The effort to deny the special character of ententional processes at that locus, and thus eliminate altogether any reference to teleological phenomena, only serves to displace these functional roles onto other loci in the explanatory apparatus. Instead of one homunculus problem, we end up creating many. And in the end the original homunculus problem remains. Removed from the body of scientific theory but unable to be silenced, it can only be hidden away, not finally eliminated. The a.n.a.logy is striking, and cautionary.

An explicit homunculus-slaying proposal for dealing with mental causality was articulated by the artificial intelligence pioneer Marvin Minsky. In his book Society of Mind, he argues that although intelligence appears to be a unitary phenomenon, its functional organization can be understood as the combined behavior of vast numbers of very stupid mindless homunculi, by which he ultimately means robots; simple computers running simple algorithms. This is a tried-and-true problem-solving method: break the problem down into smaller and smaller pieces until none appears too daunting. Mind, in this view, is to be understood as made up of innumerable mindless robots, each doing some tiny fraction of a homuncular task. This is also the approach Dan Dennett has in mind. Of course, everything depends on mental processes being a c.u.mulative effect of the interactions of tiny mindless robots. Though the homunculus problem is in this way subdivided and distributed, it is not clear that the reduction of complex intentionality to many tiny intentions has done any more than give the impression that it can be simplified and simplified until it just disappears. But it is not clear where this vanis.h.i.+ng point will occur. Though intuitively one can imagine simpler and simpler agents with stupider and stupider intentional capacities, at what point does it stop being intentional and just become mechanism?

So long as each apparently reduced agent must be said to be generating its mindless responses on the basis of information, adaptation, functional organization, and so on, it includes within it explanatory problems every bit as troubling as those posed by the little man in the head-only multiplied and hidden.

What are presumed to be eliminable are folk psychology concepts of such mental phenomena as beliefs, desires, intentions, meanings, and so forth. A number of well-known contemporary philosophers of mind, such as Richard Rorty, Stephen Stich, Paul and Patricia Churchland, and Daniel Dennett, have argued for versions of an eliminative strategy.3 Although they each hold variant interpretations of this view, they all share in common the a.s.sumption that these folk psychology concepts will eventually go the way of archaic concepts in the physical sciences like phlogiston, replaced by more precise physical, neurological, or computational accounts. Presumably the teleological framing of these concepts provides only a temporary stand-in for a future psychology that will eventually redescribe these mental attributes in purely neurological terms, without residue. Stronger versions of this perspective go further, however, arguing that these mentalistic concepts are vacuous: fict.i.tious ent.i.ties like demons and magic spells.

While these eliminative efforts superficially appear as explanatory victories, and briefly create the impression that one can re-describe a sentient process in terms of mechanism, this ultimately ends up creating a more difficult problem than before. In the examples below, we will see how the presumption that ententional properties can be eliminated by just excising all reference to them from accounts of living or mental processes inadvertently reintroduces them in ever more cryptic form.

Fractionation of a complex phenomenon into simpler component features is a common strategy in almost all fields of science. Complicated problems that can be decomposed into a number of simpler problems, which can each be solved independently, are not hard to find. The greatest successes of science are almost all the result of discovering how best to break things down to manageable chunks for which our tools of a.n.a.lysis are adequate. This is because most physical phenomena we encounter are componential at many levels of scale: stones composed of microscopic crystal grains, crystal grains composed of regular atomic ”unit cells,” crystal cells composed of atoms, atoms composed of particles, and some of these composed of yet smaller particles. Wherever we look, we discover this sort of compositional hierarchy of scale. However, this does not mean that it is universal, or that the part/whole relations.h.i.+p is as simple as it appears. Mathematicians recognize that some problems do not allow solution by operating independently on separate parts, and computational problems that do not decompose into chunks that can be computed independently are not aided by the power of parallel processing. So, although it may be nearly tautological to claim that all complex phenomena have parts and can be described in terms of these parts, it is not necessarily the case that the same complex whole can be understood one part at a time. What appear to be ”proper parts” from the point of view of description may not have properties that can be described without reference to other features of the whole they compose.

For this reason I prefer to distinguish between reducible systems and decomposable systems. Reduction only depends on the ability to identify graininess in complex phenomena and the capacity to study the properties of these subdivisions as distinct from the collective phenomenon that they compose. Decomposition additionally requires that the subdivisions in question exhibit the properties that they exhibit in the whole, even if entirely isolated and independent of it. For example, a clock is both reducible and decomposable to its parts, whereas a living organism may be a.n.a.lytically reducible, but it is not decomposable. The various ”parts” of an organism require one another because they are generated reciprocally in the whole functioning organism. Thus, a decomposable system is by definition reducible, but a reducible system may not be decomposable. Just because something is complicated and const.i.tuted by distinguishable subdivisions doesn't mean that these subdivisions provide sufficient information about how it functions, or how it is formed, or why as a complex whole it exhibits certain distinctive properties.

The question before us is whether ententional phenomena are merely reducible or are also decomposable. I contend that while ententional phenomena are dependent on physical substrate relations.h.i.+ps, they are not decomposable to them, only to lower-order ententional phenomena. This is because although ententional phenomena are necessarily physical, their proper parts are not physical parts.

At this point, the distinction may sound like an overly subtle and cryptic semantic quibble, but without going into detail, we can at least gain some idea of why it might lead to the Hydra problem. If complex ententional phenomena are reducible but not decomposable into merely physical processes, it is because components are in some sense ”infected” with properties that arise extrinsic to their physical properties (e.g., in the organization of the larger complex context from which they are being a.n.a.lytically isolated). So, a.n.a.lyzed in isolation, the locus of these properties is ignored, while their expression is nevertheless recognized. Since this is the case for each a.n.a.lyzed part, what was once a unitary ententional feature of the whole system is now treated as innumerable, even more cryptic micro-ententional phenomena.

Consider, for example, the complex DNA molecules that, by reductionistic a.n.a.lysis, we recognize as components of an organism. Each nucleotide sequence that codes for a protein on a DNA molecule has features that can be understood to function as an adaptation that evolved in response to certain demands posed by the conditions of that species' existence. But to attribute to these sequences such properties as being adaptive, or serving a function, or storing information, is to borrow a property from the whole and attribute it to the part. These properties only exist for the nucleotide sequence in question in a particular systemic context, and may even change if that context changes over the course of a lifetime or across generations. What may be functional at one point may become dysfunctional at another point, and vice versa.

As we will see below, whether we ascribe cryptically simplified ententional properties to computer algorithms or biological molecules, if we treat these properties as though they are intrinsic physical properties, we only compound the mystery. In the effort to dissolve the problem by fractionation, we end up multiplying the mysteries we have to solve.

DEAD TRUTH.

Jewish folklore of the late Middle Ages tells of a creature called a golem. A golem is formed from clay to look like a man and is animated by a powerful rabbi using magical incantations. Whereas the Almighty Jehovah had the capacity to both form a man from clay and also imbue him with a soul, the mystic could only animate his figure, leaving it soulless. Like a sophisticated robot of contemporary science fiction, the golem could behave in ways similar to a person, but unlike a normal person there would be no one home. The golem would perceive without feeling, interact without understanding, and act without discernment. It is just an animated clay statue following the explicit commands of its creator, like a robot just running programs.

If we take the homunculus as an avatar of cryptic ententional properties smuggled into our theories, we can take the golem as the avatar of its opposite: apparently mindlike processes that are nonetheless devoid of their own ententional properties. If a homunculus is a little man in my head, then the golem is a hollow-headed man, a zombie.

Zombies are closely related mythical creatures that have recently been invoked in the debates about whether mental phenomena are real or not. The popular concept of a zombie traces its origins to voodoo mythology, in which people are ”killed” and then reanimated, but without a mind or soul, and thus enslaved to their voodoo master. They are, to use a somewhat enigmatic word, ”undead.” A zombie in the philosophical sense is in every physical respect just like a person-able to walk, talk, drive an automobile in traffic, and give reasonable answers to complicated questions about life-but completely lacking any subjective experience a.s.sociated with these behaviors. The plausibility of zombies of this sort, truly indistinguishable from a normal person in every other respect but this, is often proposed as a reductio ad absurdum implication of a thoroughly eliminative view. If subjective mental phenomena, such as the sense of personal agency, can be entirely explained by the physics and neurochemistry of brain processes, then the conscious aspect of this is playing no additional explanatory role. It shouldn't matter whether it is present or not.

Stepping back from these extremes, we can recognize familiar examples of what might be termed near zombiehood. We often discover that minutes have pa.s.sed while we engaged in a complicated skill, like driving a car, and yet have no recollection of making the decisions involved or being alerted by changes of scenery or details of the roadway. It's like being on autopilot. In fact, probably the vast majority of brain processes contributing to our moment-to-moment behavior and subjective experience are never a.s.sociated with consciousness. In this respect, we at least have a personal sense of our own partial zombie nature (which probably makes the concept intuitively conceivable). And many of these behaviors involve beliefs, desires, and purposes.

The real problem posed by golems and zombies is that what appears superficially to be intrinsic purposiveness in these ent.i.ties is actually dead-cold mechanism. In the cla.s.sic medieval golem story, a golem was animated to protect the discriminated Jewish population of Prague, but in the process it ended up producing more harm than good because of its relentless, mindless, insensate behavior. According to one version of this story, the power of movement was ”breathed” into the clay figure by inscribing the Hebrew word for ”truth”--on its forehead.4 Thus animated, the golem was able to autonomously follow the commands of its creator. But precisely because the golem carried out its creator's missions relentlessly and exactly, this very literalness led to unantic.i.p.ated calamity. When it became clear that the golem's behavior could not be channeled only for good, it had to be stopped. To do so, one of the letters had to be erased from its forehead, leaving the word for death-. With this the golem would again become an inanimate lump of clay.

This myth exemplifies one of many such stories about the inevitable ruin that comes of man trying to emulate a G.o.d, with Mary Sh.e.l.ley's story of Dr. Frankenstein's monster as the modern prototype. It is no surprise that variants on the golem and Frankenstein themes have become the source of numerous contemporary morality tales. Contemporary science fiction writers have found this theme of scientific hubris to be a rich source of compelling narratives. The mystic's a.s.sumption that the golem's behavior would be fully controllable and the scientists' a.s.sumption that the processes of life and mind can be understood like clockwork have much in common. Like homunculi, golems can be seen as symbolic of a much more general phenomenon.

The golem myth holds a subtler implication embodied in its truth/death pun. Besides being a soulless being, following commands with mechanical dispa.s.sion, the golem lacks discernment. It is this that ultimately leads to ruin, not any malevolence on either the golem's or its creator's part. Truth is heartless and mechanical, and by itself it cannot be trusted to lead only to the good. The ”truth” that can be stated is also finite and fixed, whereas the world is infinite and changeable. So, charged with carrying out the implications that follow from a given command, the golem quickly becomes further and further out of step with its context.

Golems can thus be seen as the very real consequence of investing relentless logic with animate power. The true golems of today are not artificial living beings, but rather bureaucracies, legal systems, and computers. In their design as well as their role as unerringly literal slaves, digital computers are the epitome of a creation that embodies truth maintenance made animate. Like the golems of mythology, they are selfless servants, but they are also mindless. Because of this, they share the golem's lack of discernment and potential for disaster.

Computers are logic embodied in mechanism. The development of logic was the result of reflection on the organization of human reasoning processes. It is not itself thought, however, nor does it capture the essence of thought, namely, its quality of being about something. Logic is only the skeleton of thought: syntax without semantics. Like a living skeleton, this supportive framework develops as an integral part of a whole organism and is neither present before life, nor of use without life.

The golem nature of logic comes from its fixity and closure. Logic is ultimately a structure out of time. It works to a.s.sure valid inference because there are no choices or alternatives. So the very fabric of valid deductive inference is by necessity preformed. Consider the nature of a deductive argument, like that embodied in the cla.s.sic syllogism: 1. All men are mortal.

2. Socrates is a man.

Therefore.

3. Socrates is mortal.

Obviously, 2 and 3 are already contained in 1. They are implied (folded in) by it, though not explicitly present in those exact words. The redundancy between the mention of ”men” in 1 and ”man” in 2 requires that if 1 and 2 are true, then 3 must follow necessarily. Another way one could have said this is that (1) the collection of all men is contained within the collection of all mortals; and (2) Socrates is contained within the collection of all men; so inevitably, (3) Socrates is also contained within the collection of all mortals. Put this way, it can be seen that logic can also be conceived as a necessary attribute of the notion of containment, whether in physical s.p.a.ce or in the abstract s.p.a.ce of categories and cla.s.ses of things. Containment is one of the most basic of spatial concepts. So there is good reason to expect that the physical world should work this way, too.

It should not surprise us, then, that logic and mathematics are powerful tools for modeling natural processes, and that they should even provide prescient antic.i.p.ations of physical mechanisms. Deductive inference allows only one and always the same one consequence from the same antecedent. The mechanical world appears to share the same non-divergent connectivity of events, hence its predictability. Mathematics is thus a symbol manipulation strategy that is governed by the same limitations as physical causality, at least in Newtonian terms. Mechanical processes can for this reason be constructed to precisely parallel logico-mathematical inferences, and vice versa. But mathematical symbolization is finite and each side of an equation specifying a possible transformation is complete and limited.

Machines, such as we humans construct or imagine with our modeling tools, are also in some sense physical abstractions. We build machines to be largely unaffected by all variety of micro perturbations, allowing us to use them as though they are fully determined and predictable with respect to certain selected outcomes. In this sense, we construct them so that we can mostly ignore such influences as expansions and contractions due to heat or the wearing effects of friction, although these can eventually pose a problem if not regularly attended to. That machines are idealizations becomes obvious precisely when these sorts of perturbing effects become apparent-at which point we say that the machine is no longer working.

This logico-mathematical-machine equivalence was formalized in reverse when Alan Turing showed how, in principle, every valid mathematical operation that could be precisely defined and carried out in a finite number of steps could also be modeled by the actions of a machine. This is the essence of computing. A ”Turing machine” is an abstraction that effectively models the manipulations of symbols in an inferential process (such as solving a mathematical equation) as the actions of a machine. Turing's ”universal machine” included a physical recording medium (he imagined a paper tape); a physical reading-writing device so that symbol marks could be written on, read from, or erased from the medium; and a mechanism that could control where on the medium this action would next take place (e.g., by moving the paper tape). The critical constraint on this principle is complete specification. Turing recognized that there were a variety of problems that could not be computed by his universal machine approach. Besides anything that cannot be completely specified initially, there are many kinds of problems for which completion of the computation cannot be determined. Both exemplify limits to idealization.

Consider, however, that to the extent that we map physical processes onto logic, mathematics, and machine operation, the world is being modeled as though it is preformed, with every outcome implied in the initial state. But as we just noted, even Turing recognized that this mapping between computing and the world was not symmetrical. Gregory Bateson explains this well: In a computer, which works by cause and effect, with one transistor triggering another, the sequences of cause and effect are used to simulate logic. Thirty years ago, we used to ask: Can a computer simulate all the processes of logic? The answer was ”yes,” but the question was surely wrong. We should have asked: Can logic simulate all sequences of cause and effect? The answer would have been: ”no.”5 When extrapolated to the physical world in general, this abstract parallelism has some unsettling implications. It suggests notions of predestination and fate: the vision of a timeless, crystalline, four-dimensional world that includes no surprises. This figures into problems of explaining intentional relations.h.i.+ps such as purposiveness, aboutness, and consciousness, because as theologians and philosophers have pointed out for centuries, it denies all spontaneity, all agency, all creativity, and makes every event a pa.s.sive necessity already prefigured in prior conditions. It leads inexorably to a sort of universal preformationism. Paradoxically, this ultimate homunculus move eliminates all homunculi, and in the process provides no a.s.sistance in understanding our own homuncular character. But we should be wary of mistaking the map for the territory here. Logical syntax is const.i.tuted by the necessities that follow when meanings are a.s.sumed to be discrete, fixed, and unambiguous. A mechanism is a similar abstraction. Certain properties of things must be held constant so that their combinations and interactions can be entirely predictable and consistent. In both cases, we must pretend that the world exhibits precision and finiteness, by ignoring certain real-world details.

Curiously, even a.s.suming this sort of total ideal separability of the syntax from the semantics of logic, complete predictability is not guaranteed. Kurt G.o.del's famous 1931 incompleteness proof is widely recognized as demonstrating that we inevitably must accept either incompleteness or inconsistency in such an idealization. So long as the syntactic system is as powerful as elementary algebra and allows mapping of expressions to values, it must always admit to this loophole. The significance of this limitation for both computation and mental processes has been extensively explored, but the deliberations remain inconclusive. In any case, it warns that such an idealization is not without its problems. A complete and consistent golem is, for this reason, un.o.btainable.

To simplify a bit, the problem lies in the very a.s.sumption that syntax and semantics, logic and representation, are independent of one another. A golem is syntax without semantics and logic without representation. There is no one at home in the golem because there is no representation possible-no meaning, no significance, no value, just physical mechanism, one thing after another with terrible inflexible consistency. This is the whole point. The real question for us is whether golems are the only game in town that doesn't smuggle in little man-a.n.a.logues to do the work of cognition. If we eliminate all the homunculi, are we only left with golems?

As we've seen, golems are idealizations. Formal logic already a.s.sumes that the variables of its expressions are potential representations. It only brackets these from consideration to explore the purely relational constraints that must follow. We might suspect, then, that whenever we encounter a golem, there is a hidden homunculus, a man behind the curtain, or a rabbi and his magical incantations pulling the nearly invisible strings.